The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 15, 1991
Filed:
Jul. 27, 1989
Gerald L Edwards, Seattle, WA (US);
Sensorlink Corporation, Bellingham, WA (US);
Abstract
An AC current sensor comprising a generally C-shaped main coil with a fixed gap between its ends. A pair of compensating coils are positioned at fixed locations in the main coil's gap. The longitudinal axes of the compensating coils lie on an imaginary straight line which extends between the centers of the main coil's ends; and their electrical centers are each spaced the same distance from their respective ends of the main coil. A compensating coil gap is defined between the electrical centers of the compensating coils. The main coil defines a measuring recess in which the sensed AC current carrying conductor is located when a measurement is taken. When the ratio of the size of the main coil gap to the size of the compensating coil gap is equal to the square root of three, the AC current sensor's accuracy and outside signal rejection increase most rapidly with increased distance of the sensed AC current carrying conductor from the compensating coil gap, and the AC current sensor's size can be minimized. The main coil and the compensating coils are connected to a suitable amplifier and meter display.